Rocking bar grate and supporting means therefor



Sept. 13, 1949. E. c. MILLE R 2,481,938

ROCKING BAR GRATE AND SUPPORTING MEANS THEREFOR Filed Dec. 10, 1945 2 Sheets-Sheet 2 j EARLE C. MILLER Patented Sept. 13, 1949 UNITED STATES PATENT OFFICE ROCKING BAR GRATE AND SUPPORTING MEANS THEREFOR Application December 10, 1945, Serial No. 633,914

This invention relates to grates, and more particularly to fuel burning grates of the rocking or dumping type.

Grates of this type ordinarily include a series of parallel horizontal bars which are trunnioned at their ends in stationary frame members. Each bar carries a series of fuel-supportin grate clips, which may be either integral with the bar or detachably secured thereto. It is important to support the grate bars firmly in their proper positions and yet to permit their easy removal should replacement become necessary. Prior attempts to solve this problem have resulted in complicated and expensive constructions. Furthermore, these prior grate-supporting frames have been subject to frequent and costly damage from the heat of the burning fuel.

It is accordingly one object of the invention to provide a rocking or dumping grate having a comparatively simple and inexpensive frame construction which will support the grate bars properly and permit their ready removal when necessary.

It is a further object of the invention to provide a rockin or dumping grate having a grate frame in which the principal members will be well protected from the heat of the burning fuel, and such parts as are exposed to heat may be readily replaced if necessary.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

Referrin to the drawing illustrating one embodiment of the invention, and in which like reference numerals indicate like parts,

Fig. 1 is a longitudinal section through a dumping grate, the section being taken on the line I-| of Fig.5;

Fig. 2 is a fragmentary plan view of the grate;

. Fig. 3 is a longitudinal section taken on the grate member.

The embodiment illustrated comprises a furnace having a front wall to, a rear wall II, and opposed side walls l2. Within the furnace there is provided a grate including transversely extend- 4 Claims. (Cl. 126180) mg horizontal bars l4 each of which carries a series of fuel-supportin grate clips l5. As shown, these clips are formed as separate pieces which are shaped to fit the grate bars and to be slid lengthwise along the same at assembly. Trunnions l6 (Fig. 5) are provided on the opposite ends of the bars, and these trunnions rest in notches I8 formed in the upper ends of bearings l9 (Fig. 6). Each bearing I9 is in the form of a block having a slot 2!] in its lower end, these slots extending at right angles with the notches l8."

As shown in Fig. 5, the length of the bars M is such that two rows of these bars are required for the particular furnace width illustrated. In the case of wider furnaces, additional rows of bars would be provided. The two rows of bars require three series of bearings I9, and each series is supported by a separate longitudinally extending beam 22, these beams resting upon suitable foundations 23. The beams 2'2 are constructed of rolled steel bars of inverted T crosssection, each having an upwardly extending flange 24 which enters the slots 20 in the bearings I9. The bearings thus straddle the flange and are firmly supported thereby.

Each bearing I9 is held in its proper position on the beam 22 by means of a stationary grate member 26. As shown in Fig. 7, each member 26 is of T cross-section, with 2. depending vertical web 21 having a recess 28 therein of the proper size and shape to receive the upper portion of one hearing I 9. Adjacent each end of the member there is provided a dependin fork 30 arranged to straddle the beam flange 24. The rear fork 30 has a transverse hol 3| therethrough to register with a corresponding hole 32 (Fig. through the beam flange, a suitable pin or bolt 33 being inserted through these holes at assembly. It will be noted that the members 26 overlie the trunnions l6 and retain them securely in the bearing notches I8, the upper surfaces of the members 26 being substantially flush with the upper surfaces of the grate clips l5.

The beams 22 are joined at their front and rear ends by means of suitable frame members. As shown, the front ends of these beams carry saddles 35 which support a transverse horizontal dead plate 36 shaped as an upwardly-open channel with front and rear flanges, the space between these flanges being filled with refractory material 31. Metal bars 39 are bolted to the rear flange of the channel 36, the tops of these bars being substantially flush with the upper surfaces of the grate clips 5. The rear ends of the beams 22 are joined by means of transverse horizontal bars 4| which are connected to the beams by bolted clip angles 42, The tops of these bars 4| are substantially flush with the upper surfaces of the grate clips.

At the front of the furnace there is provided the usual upright metal front plate 44 which ex tends downwardly below the plane of the grate and forms the front enclosure for the usual ash pits 45 beneath the grate. This plate 44 and the front wall Ill are shaped to provide an opening 46 located immediately above the front dead plate 36 and normally closed by door 41. The plate 44 is further provided with openings 49 leading to the ash pits 45 and normally closed by doors 59.

Any suitable mechanism may be provided to turn the grate bars M in their bearings l9. shown, a short arm 52 is attached to the lower edge of each grate bar, and the arms for each row of bars are connected by an actuating bar 53. Each actuating bar is connected by-a link 54 to the piston rod 56 of a fluid-actuated motor 51- mounted on the front plate 44. By means of the motors 51 each group of grate clips 15 may be moved from their fuel burning position shown in Fig. 3 to the dumping position shown in Fig. 4 and then returned to their original positions.

The operation of the invention will now be apparent from the above disclosure. Solid fuel, such as coal, may be supplied to the grate manually through the opening 46, or if desired the coal may be' supplied by a spreader stoker in known manner through an additional wall-opening (not shown) located above the opening 46.

4 claim as new and desire to secure by Letters Patent is:

1. A grate comprising a pair of spaced parallel beams each of inverted T cross sections uniform throughout its length and with an upwardly extending flange, bearings spaced along the tops of the beams and projecting above the same, the bearings having slots in their lower ends to receive the beam flanges and upwardly open notches extending at right angles with the slots, grate bars extending transversely of the beams, the bars having trunnions on their ends which rest in the said notches, and stationary grate members mounted on the beams and overlying the bearings and trunnions.

2. A grate comprising a pair of spaced parallel beams each having an upwardly extending flange,

bearings spaced along the tops of the beams and projecting above the same, the bearings having slots intheirlower .ends to receive the beam flanges and-upwardly open notches in their upper ends extending at right angles with the slots, grate bars extending transversely of the beams, the bars having trunnions on their ends which rest in the said notches, and stationary grate members mounted above the bearings, each stationary grate-member having a downwardly open notch to receive the upper portion of the corresponding bearing-and two forks which extend In the latter case the opening 46 will serve for inspection of the fuel bed-and for access to the combustion chamber. Combustion air will be supplied to the ash pits either by forced draft or by natural draft. If natural draft is used, the ash pit doors will of course be open. When sufficient ash has accumulated on one section of the grate, the grate clips IE will be swung to their dumping positions, as shown in Fig. 4, by means of the associated motor 51. The ashes will drop into the pit 45 and can be removed through the opening 49. During the dumping operation the'trunnions [6 will turn in the notches [8 of the bearings l9.

The construction is simple and inexpensive, and the cost of maintenance will be comparatively low. No portions of the beams 22 are exposed to heat, and they should never require replacement. The same is true of the bearings 19 and the trunnion bars l4. The beams 22'are preferably made from standard rolled steel T-' bars, which cost very little and yet have great strength. The flanges 24 of the T-bars engage the slots 20 in the bearings l9 and hold them in proper alignment longitudinally of the furnace. The stationary grate members 26 maintain the bearings in the correct positions along the T-bars and protect these parts from the heat. The members 26 also protect the trunnions [6 from the heat and retain them in the bearing notches I8. The front dead plate 36 is protected from the heat by the refractory material 31 and by the readily replaceable and inexpensive bars 39. If the grate clips l5 should require replacement, the pins or bolts 33 will first be removed, so that the grate members 26 can be lifted from the beams 22, as indicated by the position of one member 26 in Fig. 1. This will release the trunnions l6 so that the grate bars M can be raised and the clips l5 removed therefrom.

Having thus described my invention, what I downwardly and straddle the beam flange at 01)- posite sides of the corresponding bearing.

3. A grate comprising a pair of spaced parallel beams each having an upwardly extending flange, bearings spaced along the tops of the beams and projecting above the same, the bearings having slots in their lower ends to receive the beam flanges and upwardly open notches in their upper ends extending at right angles with the slots, grate bars extending transversely of the beams, the bars having trunnions on their ends which rest in the said notches, and stationary grate members mounted above the bearings, each stationary grate member including an elongated horizontal fuel supporting portion with a vertical web th-erebeneath to provide a structure of T cross section, the web having a notch in its lower edge to receive the adjacent bearing, and two forks which extend downwardly from the web to straddle the beam flange at opposite sides of the bearing.

4. As an'article of manufacture, a stationary grate member comprising an elongated horizontal fuel supporting portion having a vertical web therebeneath-to provide a structure of T cross section, the web having a notch in its lower edge, and two forks depending from the web on opposite sides of the notch. 1 EARLE C. MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 525,805 Boileau Sept. 11, 1894 851,318 Ridlon Apr. 23, 1907 1,259,646 McClave Mar. 19, 1918 1,506,105 Zerbe Aug. 26, 1924 1,746,126 Moore Feb. 4, 1930 1,822,034 Jessen 'Sept.8, 1931 1,911,007 Watson May 23, 1933 1,911,664 Andre May 30, 1933 1,959,117 Thompson May 15, 193! 

